hello people, I am new to what is rapsberry and in the company that I work my boss asks me to connect the raspberry PI 3 with a Windsonic sensor which communicates by RS-232.

My idea is to occupy the ports of my pi 3 (10 RX and 8TX).
I know that the RX and TX ports tolerate a voltage ttl, for this I am occupying a rs 232 converter at lower reading levels without damaging the pi 3.

then get the reading data reflected on the screen or support me with some python code to save this data.

Note that the RPI serial input is NOT "TTL", compatible it is using 3V3 logic, not 5V (TTL) PI's are not 5V tolerant.
You need an RS232 converter that uses 3V3 levels, (based for example on a MAX3232) or you will still damage your PI.

Also people who want to say TTL can mean its using 3V3, then let me just say I think not.... 74xx 74LSxx and 74HCTxx logic (which are considered as using "TTL levels") all output 5V signals by definition.

Start in the same way you would with any other hardware/OS platform for the same purpose. For me, that would mean checking data paths to/from the RPi with a hardware data loopback test, then moving on to visually checking data acquisition from the external device, and finally to processing, displaying or storing the sensor data.

Note that the RPI serial input is NOT "TTL", compatible it is using 3V3 logic, not 5V (TTL) PI's are not 5V tolerant.
You need an RS232 converter that uses 3V3 levels, (based for example on a MAX3232) or you will still damage your PI.

Also people who want to say TTL can mean its using 3V3, then let me just say I think not.... 74xx 74LSxx and 74HCTxx logic (which are considered as using "TTL levels") all output 5V signals by definition.

when i use a usb converter rs 232 to usb directly to the notebook i can read the data, but i need to use rapsberry to be able to work with it on new development projects without the need of pc windows

You haven't previously mentioned a Notebook or Microsoft Windows, so I don't think any reply will have assumed their availabilty or use.

But since you have a usb serial converter available, is there any reason for not trying it with the RPi? The most common convertors have support already implemented within linux so maybe no additional drivers or software would be needed.

About configuring the serial port, try an entry into your favorite search engine.

To use the above code, put a wire between Rx and Tx, after you get the serial port configured, and run the code. you may have to try sPortToUse = "/dev/ttyAMA0" if sPortToUse = "/dev/serial0" does not work.

Also, I spent quite some time with configuring the serial port to work as it seems that what worked for one person did not work for me. Thus, it was make a change, run the code, make a change, run the code...

Next, you can buy some voltage level shifter, use a resistor divider network, or build you own voltage level shifters. I choose to build my own after trying out the commercially available devices. With the build my own, I get a reliable baud rate of 230400.

They are bi-directional and default to a logic level high.

Without knowing why you are deleting my postings, I will not know how...

Note that the RPI serial input is NOT "TTL", compatible it is using 3V3 logic, not 5V (TTL) PI's are not 5V tolerant.
You need an RS232 converter that uses 3V3 levels, (based for example on a MAX3232) or you will still damage your PI.

Also people who want to say TTL can mean its using 3V3, then let me just say I think not.... 74xx 74LSxx and 74HCTxx logic (which are considered as using "TTL levels") all output 5V signals by definition.

did you power the board with VCC = 3.3Volt? if you used VCC = 5V, then you might have damaged your PI!
Also, this is not a very good RS232 to "TTL" converter, and it might not work. If you power it with 3V3, the "positive" RS232 signal will also be only be 3.3V, not the normal 10V or so, if you power it with 5V, the positive RS232 signal goes up a but, but not to RS232 levels, and the receive "TTL" signal goes up to 5V, which is fatal for a PI..
a board based on the MAX3232 will be much better. it internally generates the needed RS232 signals, while using 3V3 signals on the "TTL" side.

on the PI side, perhaps you can simply connect RX to TX, to check with a serial terminal emulator program (putty) if your serial port still works.